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# AC current calculation for energy meter ADS1256 and RPI CM4

hello everyone,
i am working on some energy monitor project by using ADS1256 sensor with RPI CM4. So i wanted read the both voltage and current data from the AC supply with ADS1256 sensor which is interfacing with RPI CM4 using SPI protocol. i have used some ADS1256 library to read the voltage data and its working fine, now i want to read the current data with the same library and in my code i read the raw data and just converted it to adc voltage form like
since after this i got output in 0.009 ,0.039,0.00120… etc. So i can i make sure that the reading of current value is correct or not.

Welcome, Sagar, to the OEM forum.

You are making progress, so very well done.

You might like to read the ‘Learn’ section here to find out how to measure your mains voltage and current. There are no reports from anyone using an ADS1256, so you must understand how we use the Atmel ATMega328P and translate that so that you can use your “some ADS1256 library” and your ADS1256.

hello Robert.wall
thanks for your reply. yes i gone through that also and i followed the same procedure but i can’t make sure that i ma getting proper current at the output so that’s why i raised i query. its ok if you guys get any information please reply me and its very useful for my project.
anyway thank you so much Robert.wall

regrds,
sagar m

I really don’t understand what you mean by

You do understand that when you sample the a.c. mains voltage or current - it’s the same thing once you have either a voltage sample from a voltage transformer or a current sample from a current transformer turned into a voltage by the burden - that you get a sample at an instant in time, and the sample a few milliseconds later will be very different. You need to take a sample of each, voltage and current, many times in each mains cycle (so many hundreds or thousands of times per second) and then mathematically average the numbers to get the value a multimeter reads. It is the r.m.s (Root Mean Square) averaging process that will give you meaningful numbers.